Terminal for rail bonds



H. H. FEBREY TERMINAL FOR RAIL BONDS Filed May 14, 1940 Patented Oct. 27, 1942 UNITED TES PAT Nr orrice TERMINAL FOR RAIL 'BONDS Application May 14,

4 Claims.

This invention relates to rail bond stud terminals of the type adapted for installation by way of bottomed rail holes or recesses, and is particularly concerned with signal bond stud terminals of the type installed in bottomed holes or recesses formed in the sides of the rail heads.

Railroads now commonly specify that the holes formed in the sides of the rail heads for effecting installation of this type of stud terminal signal bond, have a diameter of 3A; of an inch and a depth of 1A; of an inch. The dimensions of these holes vary slightly according to the condition of the drill used to form them and the manipulation of this drill.

The problem of providing a stud terminal for installation by way of one of these small holes is met by the present invention in its broader form by forming a hole completely through the terminal head and the stud, the hole opening from the side of the head opposite the stud and from the end of the latter, and a malleable metal insert being positioned in the hole within the stud, the insert being sufficiently long and so positioned that its end projects beyond the end of the stud during the installation of the terminal. Installation is effected by means of a tool Which a workman positions in the hole by way of its opening in the terminal head so as to contact the outer end of the insert, the tool then being struck a few blows with the hammer by the workman so as to compress the insert and expand the same, this effecting expansion of the stud against the rail metal surrounding the rail hole. The reaction to the hammer blows is provided by reason of the other end of the insert bearing against the rail metal at the bottom of the rail hole.

The tool used by the workman is in the form of a punch and its working end must be of sufcient size to prevent its breaking when stressed by the hammer blows. A M1 inch diameter round working end is now generally considered a standard. Since the rail hole is only of an inch in diameter and experience has shown that the working end of the tool cannot safely be reduced to a diameter less than this standard, it follows that the wall of the stud surrounding the insert on which this tool works may be relatively thin.

It is necessary to remove rail bonds on occasion and a terminal constructed in the general manner described may have the disadvantage in that its thin wall may have a maximum tensile strength that is less than its maximum frictional hold in the rail hole. In such an event,

Lthe removal of a bond having this terminal might i 1940, Serial No. 335,180

involve breaking 01T the stud in thearail hole. Should this happen, the bond cannot be reused and it is necessary to drill out the stud remains from the rail hole, this being an expensive and troublesome procedure and involving the danger of undue enlargement of the rail hole. Y

Keeping the foregoing in mind, a signal bond terminal constructed as described may be modied in accordance with this invention so that l0 a punch having a full `sized working end, this being the standard 1/4` inch round cross section,

while at the same time providing a stud hav` ing a wall that is thickened to rprovide the stud with a tensile strength exceeding the holding strength of the stud in the rail hole. vantage may be attained without undesirably decreasing the holding strength of the stud in the rail hole.

The accompanying drawing illustrates signa bond terminals embodying the invention, the various figures being as follows:

Figure l, a longitudinal section rof a first example inserted in a rail head hole and ready for installation by the standard punch, and Figure 2, a'view similar to Figure 1 except- ^ing that it shows a modification and the standard punch is not used, this punch being substituted by a tool carried by the terminal itself.

More specilically, both terminals are conventional insofar as they include a head l and Aa stud 2, the latter being externally dimensioned to fit the hole formed in the side of the rail head when this hole is' of the dimensions now commonly specified by the railroads. The punch 3 is also conventional in that its working end is of a 1A; inch round cross section. It might be mentioned that this punch 3 is usually provided With a handle for positioning it and has a head the head, which is of standard diameter, theV remainder 5 of the hole being of reduced .diameter within a portion ofthe head and a portion of the stud adjacent its junction with the head, this remainder or portion 5 of the hole flaring from the plane of this junction to the end of the stud where it has a diameter the same as the portion 4 of the hole. This construction proit has the advantage of permitting the use of' This ad- I opposite its working end, which is struck by the vides the stud at its junction with the head, with a wall that is much thicker than could be provided if the terminal hole was made cylindrical with a diameter accommodating the standard punch, the wall thickness then reducing to the stud end.

For example, assuming the stud to have a diameter of slightly less than 3A; of an inch and the portion 5 of the hole to have a diameter of about Tse of an inch at the plane of the junction between the stud and the head, and to then conically flare to a diameter slightly larger than 1A of an inch, the stud is provided with an adequately greater tensile strength. It will be noted that the portion of the hole 5 between this plane of the junction of the stud and the head, and the inner end of the portion 4, is cylindrical, the junction between the portions 4 and 5 of the hole being in the form of an annular shoulder 6 providing a relatively abrupt oiset.

Expansion of the stud 2 is effected by a malleable metal insert l, this insert being contoured to t the portion 5 of the hole and being sulficiently long so that its smaller end extends up into the portion 4 of the hole while its larger end extends beyond the end of the stud 2. It follows that expansion of the insert 1 may be effected in the usual manner by the use of the usual tool working through the opening of the portion 4 of the hole against that end of the insert l, yet the tensile strengthl of the stud exceeds its maximum possible holding power in the rail hole by reason of its thickness increasing as the tensile stress applied to its wall increases when the terminal is forcibly withdrawn from its installed position, there being no danger of fracturing the stud because of this.

One important advantage of the terminal described is that it can be used even though the depth of` the rail hole is greater than the length of the stud. This follows from the fact that when the rail hole is too long, the punch 3 shoves the insert l along until its inner end contacts the rail hole bottom, the insert then expanding and eifecing expansion of the stud 2. To obtain this action, the insert, of course, must be made of adequate length.

The insert 1, made of copper, is shown as being cylindrical through its portion within the cylindrical section of the portion 5 and with its outer end extending into the standard size portion 4 of the terminal hole. Thereforey when the tool 3 is struck with the rst blow of the hammer, the iirst action is to flatten out the outer end of the insert, the flattened metal upsetting onto the annular shoulder 6 and, since this shoulder is relatively abrupt, transmitting a part of the force of the first hammer blow and of succeeding hammer blows, longitudinally through the upset insert metal into the shoulder and so through the head into the wall of the stud 2. It is to be understood that a large portion of the force of the hammer blows goes into longitudinal compression of the insert so as to effect its lateral expansion with consequent expansion of the stud.

One di'iculty experienced with stud terminals is the tendency of the terminal stud to retreat from the rail hole while being expanded by the insert. However, in the case of the present terminal, this tendency is counteracted by the transmission of a portion of the insert expanding force longitudinally into the stud wall so as to prevent the stud from retreating from the rail hole. At the same time, this force transmitted into the stud wall tends to shorten the stud wall which by itself results in expansion of the stud through thickening of its wall, the latter, at the same time, being expanded by the expanding insert.

In the case of the modified terminal illustrated by Figure 2, the same parts are used and are, therefore, similarly numeraled excepting that they are identied by the letter a.

It will be noted that the punch 3a is in the form of a tool included by the terminal as a part of the same. This tool may be retained in the hole portion 4 by being press-tted into place, it being understood that while it is not necessary that this tool be so sturdy as when the removable punch is used which must effect the installation of a large number of bonds, it is still desirable to have it as strong as it possibly can be made. In other words, a terminal of the type having the tool built into it is useless if the tool fails after the rst one or two hammer blows, or when the terminal is reused.

Another difference in this modification is that this insert has its outer end attened at the time of the manufacture of theterminal so that it completely lls the portion lla of the hole that is of standard size, it further differing in that the portion 5a of the hole is cylindrical, it having a diameter throughout its length equalng the smallest diameter of the portion 5 of the rst example. By preflattening or upsetting this end or head of the insert, the rst hammer blow transmits the same portion of its force longitudinally into the stud wall as do subsequent blows, and by making the portion 5a cylindrical, the stud wall is made relatively thick throughout its entire length whereby when it receives the longitudinal force, it has less tendency to be expanded thereby and more tendency to provide a greater force preventing its extrusion from the rail hole during its expansion by the insert.

It is to be understood that in the case of either example, the outer end of the insert may or may not be preflattened or upset at the time of its manufacture, and the terminal may be made to either have the tool 3a as a part or to accommodate the removable type of tool such as the punch 3. In all cases, it is necessary to consider the tool as the part of the terminal, because one of the advantages of the present invention is its ability to use a larger sized tool than would be possible if the stud wall were thickened in the case of prior art terminal constructions.

I claim:

1. A rail bond terminal having a head and a stud with a hole formed through both the head and the stud, and a, metal insert positioned in the hole with one end extending beyond the stud end and its other end terminating inside the head, the insert being shorter than the hole and its portion adjacent and extending beyond the stud end being at least as malleable as its remainder.

2. A rail bond terminal having a head and a stud with a hole formed through both the head and the stud, and a metal insert positioned in the hole with one end extending beyond the stud end and its other end terminating inside the heady the portion of the hole within the stud being flared toward the stud end and the insert filling the ared portion of the hole, the insert being shorter than the hole and its portion adjacent and extending beyond the stud'end being at least as malleable as its remainder.

3. A rail bond terminal having a head and a stud with a hole formed through both the head and the stud, and a metal insert positioned in the hole with one end extending beyond the stud end and its other end terminating inside the head, a portion of the hole in the head including the opening to the hole being of larger diameter than at least the portion of the hole at the junction between the stud and the head, and the insert extending into the first named portion, and a tool for insertion in the rst named portion and which is of larger diameter than the second named portion of the hole, the insert being shorter than the hole and its portion adjacent and extending beyond the stud end being at least as malleable as its remainder.

4. A rail bond terminal having a head and a stud with a hole formed through both the head and the stud, and a malleable metal insert positioned in the hole with one end extending beyond the stud end and its other end terminating inside the head, a portion of the hole in the head including the opening to the hole being of larger diameter than at least the portion of the hole at the junction between the stud and the head and the insert extending into the first named portion, and a tool for insertion in the first named portion and which is of larger diameter than the second named portion of the hole, the junction between the rst and second named portions of the hole providing an annular shoulder for receiving metal upset from the insert by compression of the same so as to transmit some of the insert compressing force longitudinally into the stud.

HAROLD H. FEBREY. 

